Controlling electric arcs



March 17, 1931. K. STROBEL. 1,796,969

CONTROLLING ELECTRIC ARCS' Filed June 5, 1929 INVENTOR.

Karl Strobe! A TTORNE Y.

Patented Mar. 17, 1931 UNITED STATES PATENT OFFICE KARL STBOBEL, OFMILWAUKEE, WISCONSIN, ASSIGNOR TO A. 0. SMITH CORPORA- TION, OIMILWAUKEE, WISCONSIN, A CORPORATION 01 NEW YORK CONTROLLING ELECTRICARCS Application filed June 8,

This invention relates to a method of controlling and stabilizing anelectric are. I

The invention is particularly applicable to electric arcs employed inthe welding and 5 fusing of metals wherein an electric arc isestablished between a fusible metallic weldrod and the parts to bewelded and the metal from the rod is projected through said are andintegrally united with the parts to be 11) Welded.

One of the objects of the invention is to increase the penetrating powerof the are so that the same may fuse the parts to be welded to depthsgreater than have heretofore been 15 obtainable.

Another object of the invention is to stabilize and control the are soas to cause the metal being deposited thereby to be projected onto theparts to be welded in a steady stream of minute particles.

A further object of the invention is to conserve the electrical energyemployed for establishing and maintaining the are by reducing the amountof heat loss through dissipation of the heat interiorly of the articlebeing welded.

A further object of the invention is to obtain a weld having a uniformstructure and having other desirable commercial qualities.

Having these and other objects in view, the invention resides in animprovement in controlling an electric are by surrounding the same witha magnetic coil wherein the magnetic field of force resulting therefrom1s utilized to desirably control and stabilize the arc.

The invention is best understood by referring to the accompanyingdrawings in which the invention is shown as applied to the art of arcwelding.

In the illustration, the numeral 1 indicates a weldrod which may becomposed of fusible metallic material or of non-fusibleelectro-conductive material such as carbon. The weldrod is connected toone terminal of a source of welding energy and the parts 2 to be weldedare connected to the other terminal of the source of welding energy asis well understood in the industry. Concentric to the weldrod and spaceda 1929. Serial No. 388,086.

suitable distance from the same is a tapered coil 3 of suitableelectro-conductive material which coil is supported-in any suitablemanner such as by the fingers 4 depending from a r1ng'5 which is in turnsupported by a suit- 5 able supporting post 6. The coil is preferablytapered and may include any suitable number of turns about the weldrod.The taper is preferably so proportioned and the coil s0 positioned withrespect to the weldrod that the apex of the taper will be somewhereadjacent the center of the arc as is shown by the dotted lines in thefigure. The coil is preferably connected to the welding circuit and inseries with the arc.

The results obtained from the coil when shaped and positioned as aboveset forth indicate that the coil sets up desirable magnetic conditionsaround the are so as to cause the same to penetrate into the parts beingwelded to a degree much greater than would otherwise be possible byemploying electrodes having the same current densities. The magneticfield surrounding the arc tends to stabilize the same and to cause themetal from the weldrod to be projected in a steady stream of minuteparticles upon the parts being united. By tapering the coil as shown,results indicate that the most desirable magnetic conditions and abetter control and stabilization of the arc may be effected when the arcis near the apex of the taper, although it is understood that theposition of the apex may be varied to a considerable degree withoutdeparting from the spirit of the inven- 85 tion.

While the invention readily lends itself to the art of arc welding, itmay well be applied to stabilizing and controlling other arcs, such asthose used in electric furnaces and are lam s.

Having thus described the invention, what is desired to be secured byLetters Patent is:

1. In an apparatus for controlling an electric are, a pair of spacedelectrodes in arcing relation to each other, a tapered coil concentricto and spaced from one of said elec trodes, the apex of the taper. beingsubstantially at the center of-the arc, and means for passmg an electriccurrent through said coil. 10o

2. In an apparatus for electric arc welding,

a fusible metallic weldrod in arcing relation to the parts to be welded,a tapered coil encircling said weldrod and positloned to have 5 its a exat the arc, and means connecting the coil in series with the arc.

In witness whereof I have signed my name at Milwaukee, Wisconsin, this29th day of May, 1929. KARL STROBEL.

